The present invention relates to facsimile machines, and specifically to a convertible facsimile machine designed to receive disposable paper supply cartridges providing a variety of types of paper.
A facsimile machine is designed to exchange pictorial images with another remotely located facsimile machine through the use of telephone lines. Each facsimile machine can normally operate either in the role of the "receiver" or "transmitter" of the pictorial image, and contains means for manipulating the image in the form of small picture elements. These picture elements or "pels" are tiny gray or white "windows" whose size ranges from 3 to 5 mils square.
Each facsimile machine possesses five (5) essential elements which are required in the image transfer process:
1) a scanner which reads the white, black or gray color information of each pel from the image of each original document;
2) a modem which controls the transmission of pel data over the telephone lines;
3) a printer which reconstructs the image when in the receiving role or mode by printing on paper the black or gray data at each of the pel locations;
4) a keyboard which allows the facsimile operator to set the modes of operation and to program the telephone numbers of remote receiving facsimile machines; and
5) a central controller, usually a microcontroller, whose purpose is to control the interaction between these elements.
Certain commercially available facsimile machines require that the normal office or home telephone be interconnected to the machine base for the purpose of handling the telephone calls transmitting pel data. However, the majority of machines contain built-in telephones and can be used merely as telephones. In addition, most facsimile units have the ability to reproduce images locally. A "COPY" mode allows an original document to be copied locally, much like an office copier. These machines thus have triple functions, and are often referred to as "FAX/PHONE/COPIERS" in advertising.
The printer elements of conventional facsimile machines are provided for use either with paper having a thermally activated transfer coating (hereinafter referred to as "thermal paper") or with so-called plain paper. A disadvantage of thermal paper is that facsimile messages printed thereon often become curled upon their ejection from the machine, causing difficulty in achieving these messages. Thus, a standard operating procedure in many offices is to make a plain paper copy of every thermal paper facsimile for archival purposes. Another disadvantage of thermal paper is that it often turns yellow in as little as a few days after the message is printed by the machine. Also, it is often difficult to write on thermal paper with a ball-point pen.
In order to address these and any other disadvantages of thermal paper, facsimile machines have been designed for use with plain paper. Such machines use electrophotographic, xerographic, or thermal transfer technology to produce the facsimile image, and as a result, are significantly more expensive than thermal paper machines. Thus, a prospective facsimile machine purchaser must choose between thermal paper machines, with their lower cost and somewhat less desirable paper, and the more expensive plain paper machines. This is truly a dilemma for an economically constrained buyer.
In both types of conventional machines, the paper is provided rolled on a spool, and must be carefully threaded through the machine by hand. In busy offices, it is not uncommon for message transmission to be disrupted during the changing of the paper.
A further disadvantage of conventional facsimile machines, regardless of the type of paper used, is that, through use, the print head becomes soiled. This results in unwanted lines being printed on the facsimile message and/or in blurred or otherwise illegible type. Printing head cleaning kits are now being made available; however, they are time consuming to use.
Facsimile machines which may accept both thermal and plain paper are now available, but the buyer must pay the cost penalty for a "plain paper" unit at the point of purchase of the machine. Thus, there is a need for a facsimile unit which is available at "thermal" costs, and which can later be made "upgradable by the user" to accept plain paper. In this way, the "choice of paper" dilemma is removed from the buying decision at point of purchase of the machine. There is also a need for a more convenient system for changing facsimile paper, and for cleaning soiled facsimile print heads. In addition, there is a need for a more convenient way to package, store, and dispose of facsimile paper and ribbon supplies. Lastly, there is also a need in more economically constrained environments, such as home offices, to have facsimile papers that are adaptable to the immediate task. For instance, the more economical thermal paper is appropriate for the normal facsimile receiving mode. However, when an important document such as a contract or a drawing is expected to be received, it would be beneficial to have the capability of receiving the document, and/or copying it, on plain paper. It is apparent that a convenient method is needed to adapt the machine to a specified type of paper quickly and conveniently.